The invention relates to an apparatus for use in connection with removal of elements, especially exogenous antibodies, from blood or plasma flowing in an extracorporeal blood circulation system of a patient, where said apparatus comprises a container adapted to receive an adsorbent, and where said container is provided with an inlet and an outlet adapted to be connected to an inlet conduit and an outlet conduit, respectively, forming pat of the blood circulation system.
It is known inter alia from WO 92/12730 to treat cancer by way of injecting antibodies containing a cytocide into the blood circulation system of a patient. From the same publication it is also known to limit the side effect of these antibodies by removing them again after a suitable period of time. In order to ensure a good result of the use of antibodies, said antibodies are administered in relatively large amounts. However, only a very small portion of the antibodies, ordinarily less than 1%, reach the cancer cells. When the remaining portion of the antibodies stay for a long period of time in the patient, said portion may involve a risk of having an injurious, damaging effect, such as when the antibodies for instance contain radioactive material.
It is also known to use a so-called column housing for removing the antibodies by way of adsorption. A suitable adsorbent is placed inside the column housing, said adsorbent ensuring the necessary effect during the passage of the blood. In the known systems the blood is directed through a pump and a device for separating the plasma to the column housing, whereby the blood cells are directed round the column housing and returned to the plasma after said plasma has passed the column housing. The column housing comprises a container with an inlet and an outlet in their respective ends. The inlet is connected to an inlet conduit and the outlet to an outlet conduit, and a shut-off valve is arranged in each of these conduits. A bypass conduit extends round the container, and one end of said bypass conduit is connected to the inlet conduit before the shut-off valve when seen in the flowing direction of the plasma, and the other end of said bypass conduit is connected to the outlet conduit after the shut-off valve therein. The bypass conduit comprises per se at least one shut-off valve. When this column housing is used, the flow through the bypass conduit is allowed by a closing of the shut-off valves in the inlet conduit and the outlet conduit in various situations, such as in connection with removal of air from the conduit system, in connection with a clogging up of the passageway through the column housing caused by for instance coagulation, and in connection with the termination of the treatment whereby a saline solution is used for expelling the plasma from the conduit system.
Such a conduit system with a column housing and a bypass conduit extending round said column housing is relatively complicated and difficult to handle. In addition, it is not suited for treatment of ordinary blood, but only of blood plasma because a high risk exists of the blood coagulating in the bypass conduit while the flow therethrough is interrupted.
The object of the invention is to provide an apparatus which presents a relatively simple structure, which is easy to operate and suited for treatment of ordinary blood.
The apparatus according to the invention is characterised in that the container comprises an inlet chamber, an adsorption chamber for receiving the adsorbent, and an outlet chamber, whereby the chambers are arranged in sequence when seen in the flow direction of the blood through the container and are separated by means of filter units allowing a passage of the blood, that the inlet and the outlet are arranged adjacent one another on the portion of the container wall which together with a filter unit defines the outlet chamber and which is associated with a common movable valve means, where said valve means is adapted in a first position to connect the inlet and the outlet directly with their respective passages in the container wall, and where said valve means is adapted in a second position to connect the inlet and the outlet with their respective ends of a bypass-forming channel in the container wall, and that the passage associated with the inlet communicates with a transfer channel ending in the inlet chamber whereas the passage associated with the outlet is open into the outlet chamber.
As a result, it is sufficient to operate only one valve means, and in addition the bypass channel is relatively short. The relatively short bypass channel involves a risk of coagulation of only a very small portion of blood, said portion, if any, being easily absorbed by the patient. The apparatus in question can, of course, also be used for treatment of blood plasma. By the conventional use of the apparatus, the blood flows through the passage at the inlet of the container and then through the transfer channel to the inlet chamber, and subsequently the blood passes the filter unit therein and flows through the adsorption chamber containing the suitable adsorbent. From here the blood passes the second filter unit and enters the outlet chamber, whereafter it leaves said outlet chamber through the passage and flows to the outlet and is returned to the patient in a conventionally known manner. When it is desired to open the bypass circulation system, the valve means is activated so as to interrupt the flow through the adsorbent and open the bypass channel.
According to the invention the valve means may be permanently connected to an inlet stub and an outlet stub with the result that said stubs are easily moved together. The valve means may particularly advantageously be rotatable.
Moreover, the inlet and the outlet may according to the invention be associated with a cover accommodated on the container, said cover comprising an inner cover member in sealing connection with the opening of the container as well as an outer cover member which is secured to the container and comprises an opening surrounding the valve means, where said valve means comprises an at least partially circumferential, radially projecting flange which is received in a corresponding recess between the two cover members, stopping means being provided for stopping the rotation of the valve means at the two functional positions. The resulting embodiment is particularly simple to manufacture and operate.
In addition, the container may according to the invention be substantially axially symmetrically structured, the passage of the inlet and the associated transfer channel being arranged coaxially with the axis of symmetry of the container. In this manner an embodiment is ensured which is easy both to sterilize, to fill with adsorbent, to empty of air prior to the use as well as easy to manufacture.
According to the invention the filter units may in a particular simple manner be disc-shaped and provided with a porous filter cloth embedded in a carrying plastic structure.
Each filter unit may according to the invention particularly advantageously be retained in a sealing abutment against an associated circumferential abutment face on the inner wall of the container, said filter unit at the inlet chamber being retained by a separately secured bottom member and said filter unit at the outlet chamber being retained by the inner cover member.
Finally the transfer channel may according to the invention be formed by a tube permanently connected to the inner cover member, said tube comprising outer circumferential grooves co-operating by way of a snapping effect with a central annular member of the carrying structure of each filter unit.